Vacuum Dust Extraction Apparatus for a Percussive Air Tool

ABSTRACT

A vacuum dust extraction system includes a snorkel coupled to the implement end of an air tool, a dust bellows surrounding the air tool&#39;s implement and fastened to the outboard end of the snorkel, a pneumatically powered water filtration industrial vacuum, and a suction hose coupling the snorkel to the vacuum. The apparatus features an improved coupling arrangement for attaching the snorkel to the barrel of the tool driver that permits the apparatus to work with a wide assortment of air tools, and an improved water filtration apparatus housed in the vacuum.

RELATED APPLICATIONS

This application claims priority based on the Provisional PatentApplication No. 62/555,909, filed Sep. 8, 2017, and the ProvisionalPatent Application No. 62/666,789, filed May 4, 2018.

TECHNICAL FIELD

This invention relates to a vacuum dust extraction apparatus for apercussive air tool such as a chisel hammer or rivet buster.

BACKGROUND OF THE INVENTION

Pneumatically operated percussive air tools such as pick or chiselhammers, rivet busters, and so forth are frequently used in industrialapplications, and various expedients have been employed to minimize orcontain airborne dust produced by the impacting action of the tool. Asdisclosed, for example, in the U.S. Pat. No. 7,740,086 to Bleicher etal. and U.S. Pat. No. 9,022,702 to Kasuya et al., this can be achievedwith a dust containment hood attached to the implement end of the airtool's housing and an industrial vacuum that draws dust out of the dustcontainment hood and captures it for later disposal.

While this approach is effective, it is not particularly practicalbecause industrial vacuums typically rely on mechanical filtration inthe form of paper cartridges or other filter elements that either failto filter out or become quickly clogged by small dust particles of thesort generated by the operation of a percussive air tool. Additionally,air tools can vary considerably depending on their rating and type, sothat a dust containment hood designed to work with one type of air toolwill not necessarily work with other air tools. Accordingly, what isneeded is an improved vacuum dust extraction apparatus including anindustrial vacuum uniquely suited to industrial worksites and extractionof percussive air tool dust, and a more universal coupling arrangementfor attaching the dust containment portion of the apparatus to the airtool.

SUMMARY OF THE INVENTION

The present invention is directed to an improved vacuum dust extractionapparatus for a percussive air tool for removing and capturing workpiecedust created by the impacting action of the air tool's implement. Theimproved system includes a snorkel coupled to the implement end of theair tool, a dust bellows surrounding the implement and fastened to theoutboard end of the snorkel, an air-powered water filtration industrialvacuum, and a suction hose coupling the snorkel to the vacuum.

The apparatus features an improved coupling arrangement for attachingthe dust containment portion of the apparatus (that is, the snorkel andbellows) to the air tool in a way that permits the dust containmentportion of the apparatus to work with a wide assortment of air tools.The improved coupling arrangement includes a tubular coupler removablyjoined at one end to a cylindrical sleeve on the snorkel and at theother end to a cylindrical sleeve on the air tool. Both cylindricalsleeves have the same outside diameter, and each is provided with acircumferential groove on its exterior periphery. The tubular couplerhas a pair of spaced circumferential grooves on its interior peripherythat align with the circumferential grooves of the sleeves when thecylindrical sleeves are inserted into opposite ends of the coupler, andretainer springs inserted into slot openings in the coupler slip intoannular spaces defined by the aligned circumferential grooves tosecurely join the dust containment portion of the apparatus to the airtool. In a first embodiment, the cylindrical sleeve of the air tool isan extended outer sleeve of a rivet buster; in a second embodiment, thecylindrical sleeve of the air tool is a modified retainer of a chiselhammer, and in a third embodiment, the cylindrical sleeve of the airtool is a clamshell adapter that fits over an air tool's retainer.

The apparatus also features an improved industrial vacuum that createsadequate suction for removing dust while efficiently filtering the dustfrom the suction airflow. The improved vacuum includes a canisterpartially filled with water (referred to herein as the confined water),an air inlet port coupled to the dust containment hood portion of theapparatus via the suction hose, a vacuum unit mounted on the lid of thecanister for creating a vacuum-induced airstream through the suctionhose and canister, and a water filtration unit through which theairstream must flow before being admitted into the canister andexhausted to atmosphere through the vacuum unit. The water filtrationunit includes a down tube coupled to the air inlet port of the canister,and cylindrical velocity ring. The velocity ring rests on the floor ofthe canister in a manner that allows the confined water to enter andpartially fill the velocity ring. The down tube extends downward fromthe air inlet port and through the velocity ring substantially to thefloor of the canister, and includes an air exit port through which theinlet air is released into the interior volume of the velocity ring wellbelow the water level in the velocity ring.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of the vacuum dust extraction apparatus of thisinvention, as applied to a percussive rivet buster air tool.

FIG. 2 is an exploded isometric diagram of the dust containment portionof the dust extraction apparatus of FIG. 1.

FIG. 3 is diagram of the vacuum dust extraction apparatus of thisinvention, as applied to a percussive chisel hammer air tool.

FIG. 4 is an exploded isometric diagram of the dust containment portionof the dust extraction apparatus of FIG. 3.

FIG. 5 is an exploded diagram of a clamshell adapter for the vacuum dustextraction apparatus of this invention.

FIG. 6 is an isometric cross-sectional diagram of the water filtrationindustrial vacuum of FIGS. 1 and 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In general, the vacuum dust extraction apparatus of this invention isapplicable to any percussive air tool, such as chipping hammers,riveting hammers, rivet busters, demolition tool drivers, pavementbreakers, rock drills, and so on. FIGS. 1-2 illustrate an application ofthe vacuum dust extraction apparatus to a first type of percussive airtool, a rivet buster; and FIGS. 3-4 illustrate an application of thevacuum dust extraction apparatus to a second type of percussive airtool, a chisel hammer. The illustrated coupling arrangements can beapplied to other types of air tools as well.

Referring to FIGS. 1-2, the vacuum dust extraction apparatus of thisinvention is illustrated as applied to an otherwise conventionalpercussive rivet buster air tool. The rivet buster has a tubular barrel3 fitted with a handle 1 at one axial end and a retainer 7 at the otheraxial end. The handle 1, which may take various other shapes (D-shaped,or T-shaped, for example), includes an inlet port 1 a adapted to becoupled to a source of compressed air by the air hose 23, an internalair passage coupling the inlet port 1 a to a piston 4 by way of acontrol valve (not shown) operated by a trigger 1 b integrated into thehandle 1.

The implement or tool 15, a chisel in the illustration of FIG. 1, isreceived within the barrel 3 and an inner sleeve 8, and the retainer 7is locked onto the barrel 3 with a retainer spring 6 to retain thechisel 15 within the barrel 3. Inward movement of the chisel 15 islimited by the inner sleeve 8, while outward movement of the chisel 15is limited by an outer sleeve 9 and a tubular rubber bumper 10. Theinboard end of the outer sleeve 9 is flanged; the rubber bumper 10 isdisposed about the outer sleeve 9, and sandwiched between the flangedend of outer sleeve 9 and the outboard end of retainer 7. The outboardend of the outer sleeve 9 extends through the retainer 7, and terminatesin a cylindrical sleeve 9 a having a circumferential groove 9 b on itsexterior periphery, as best seen in FIG. 2. In a conventional rivetbuster, the outer sleeve 9 would be entirely disposed within theretainer 7, but according to the present invention, the outboard end ofthe outer sleeve 9 is lengthened so as to protrude through the retainer7 and provide an attachment point for the dust containment portion ofthe subject vacuum dust extraction apparatus, as described below.

The dust containment portion of the apparatus is generally designated inFIGS. 1-4 by the reference numeral 11. In general, the dust containmentportion 11 includes a flexible dust bellows or boot 14 withaccordion-style pleating, a snorkel 13, and a flexible suction hose 19coupled to an outlet pipe 13 a of the snorkel 13. The body of bellows 14surrounds the chisel 15, extending substantially to the chisel's tip asshown in FIG. 1. Preferably, the bellows 14 is relatively transparent soas to not obstruct the user's view of the chisel 15 and the workpiece inthe area of the chisel's tip; this also allows the user to visiblyconfirm that the bellows 14 is not getting clogged with dust. Theinboard end of dust bellows 14 slides over a cylindrical sleeve 13 b onthe outboard end of snorkel 13. There is an annular cavity 25 betweenthe chisel 15 and the inner periphery of the snorkel sleeve 13 b so thatdust generated by the action of the chisel 15 and drawn into the dustbellows 14 passes through the cavity 25 and the snorkel outlet pipe 13a. The inboard end of the snorkel 13 terminates in a cylindrical sleeve13 c having an outside diameter equal to that of the cylindrical sleeve9 a of outer sleeve 9. And similar to the cylindrical sleeve 9 a, thecylindrical sleeve 13 c has a circumferential groove 13 d on itsexterior periphery, as best seen in FIG. 2.

The snorkel 13 is coupled to the air tool's outer sleeve 9 by a tubularcoupler 12. The tubular coupler 12 has an inside diameter slightlylarger than the outside diameters of the cylindrical sleeves 13 c and 9a, and is provided with a pair of spaced circumferential grooves 12 a,12 b on its interior periphery that are axially aligned with a pair ofslot openings 12 c, 12 d in the sidewall of the coupler 12. When thecoupler 12 is slid over the cylindrical sleeve 13 c on the inboard endof snorkel 13, the circumferential grooves 12 a and 13 d become axiallyaligned, and the coupler 12 is locked onto the snorkel 13 by a rubberO-ring 15 a that fills the annular space defined by the alignedcircumferential grooves 12 a and 13 d. Likewise, when the coupler 12 isslid over the extended cylindrical sleeve 9 a on the outboard end ofouter sleeve 9, the circumferential grooves 9 b and 12 b become axiallyaligned, and the coupler 12 is locked onto the outer sleeve 9 by aretainer spring 15 b inserted into the coupler's slot opening 12 d; whenthe retainer spring 15 b is so inserted, it enters and fills an annularspace defined by the aligned circumferential grooves 9 b and 12 b, andits tang 16 protrudes through the slot opening 12 d to facilitate laterremoval of the retainer spring 15 b.

Referring to FIGS. 3-4, the vacuum dust extraction apparatus of thisinvention is illustrated as applied to an otherwise conventionalpercussive chisel hammer air tool. The chisel hammer is like the rivetbuster of FIGS. 1-2, except that there are no sleeves 8 and 9 to limitthe percussive motion of the chisel 15. In this case, the commonattachment point for the dust containment portion 11 of the vacuum dustextraction apparatus is provided by a modified retainer 7′ that is usedin place of the conventional retainer 7 of FIGS. 1-2. The modifiedretainer 7′ is unique in that its outboard end terminates in acylindrical sleeve 7 a. The cylindrical sleeve 7 a has an outsidediameter equal to that of the cylindrical sleeve 13 c of snorkel 13, andlike the extended outer sleeve 9 of FIGS. 1-2, the cylindrical sleeve 7a has a circumferential groove 7 b on its exterior periphery, as bestseen in FIG. 4. The coupler 12, O-ring 15 a, and retainer spring 15 b ofFIGS. 3-4 are identical to those described above in reference to FIGS.1-2, only in this case, the retainer spring 15 b locks the coupler 12onto the cylindrical sleeve 7 a of modified retainer 7′. That is, whenthe coupler 12 is slid over the cylindrical sleeve 7 a, thecircumferential grooves 7 b and 12 b become axially aligned, and thecoupler 12 is locked onto the modified retainer 7′ by the retainerspring 15 b, which when inserted into the coupler's slot opening 12 d,fills the annular space defined by the aligned circumferential grooves 7b and 12 b, with the tang 16 protruding through the slot opening 12 d.

FIG. 5 illustrates yet a third embodiment of an air tool attachmentpoint for the coupler 12. In this embodiment, the air tool componentsare unchanged (as designated by the air tool barrel 3 and retainer 7),and the coupler attachment point is provided by a two-piece clamshelladapter that fits over the retainer 7. As viewed in the exploded view ofFIG. 5, the clamshell adapter includes upper and lower halves 17 and 18that are oppositely positioned about the retainer 7 and joined to form atubular component that effectively encases the retainer 7. The adapterhalves 17, 18 have outboard sleeve portions 17 a, 18 a withcircumferential grooves 17 b, 18 b. When the adapter halves 17, 18 arejoined to encase the retainer 7, the sleeve portions 17 a, 18 a form acylindrical sleeve that extends outboard of the retainer 7, and thecoupler 12 is joined to this cylindrical sleeve. That is, when thecoupler 12 is slid over the adapter's cylindrical sleeve, thecircumferential grooves 17 b, 18 b and 12 b become axially aligned, andthe coupler 12 is locked onto the adapter's cylindrical sleeve by theretainer spring 15 b. The exterior peripheries of the adapter halves 17and 18 are provided with a set of three spaced and axially alignedcircumferential grooves so that when the adapter halves 17 and 18 arejoined, they are secured together by three rubber O-rings (not shown)seated in the peripheral grooves.

Regardless of the air tool configuration, the suction hose 19 is coupledto a water filtration industrial vacuum 30. As best seen in FIGS. 1 and3, the vacuum 30 generally comprises a standard 5-gallon metal pail orcanister 32 and a metal lid 34 releasably secured to the upper rim ofcanister 32. The downstream end of suction hose 19 is fastened to theinlet of a vacuum port 38 mounted on the lid 34, and a vacuum unit 40also mounted on the lid 34 creates a suction in the canister 32 thatdraws dust-laden air from the dust containment portion 11 into thecanister 32, and then exhausts clean air to atmosphere. Although notshown in FIGS. 1, 3 and 6, the sidewall of the canister 32 preferablyincludes a number of circumferential ribs to impart additional stiffnessand resistance to flexure.

The vacuum unit 40 is preferably a pneumatic vacuum operated bycompressed air supplied from an air hose 33; the vacuum unit 40 includesa venturi 40 a, and the compressed air is directed into venturi 40 athrough a distributed array of internal air passages (not shown) tocreate suction upstream of venturi 40 a. In this case, the downstream oroutlet end of the venturi 40 a is vented to atmosphere through anexhaust diverter 44, and the upstream or inlet end of venturi 40 iscoupled to a venturi mount 46 fastened to the lid 34 of the vacuumcanister 30.

As illustrated in FIG. 3, a volume of water 44 (referred to herein asthe confined water) is placed in the bottom of the canister 32, to adepth of approximately 3 inches, and the dust-laden air enteringcanister 32 via vacuum port 38 is cleansed of dust by a water filtrationunit 50 (described below in reference to FIG. 6) housed within thecanister 32 and partially submerged in the confined water 44. As shownin FIGS. 3 and 6, the vacuum 30 also includes a baffle disk 59 disposedin the upper portion of the canister 32, so that the cleansed airexiting water filtration unit 50 passes through the baffle disk 59 priorto being exhausted to atmosphere though the venturi 40 a of vacuum unit40. The purpose of the baffle disk 59 is primarily to prevent any of theconfined water 44 from entering the venturi 40 a.

Referring now to FIG. 6, the water filtration unit 50 includes acylindrical velocity ring 52 supported on the bottom or floor 32 a ofcanister 32, and a pipe arrangement 54 extending downward from thevacuum port 38 and into the velocity ring 52. In the illustratedembodiment, the velocity ring 52 is constructed of a section of six (6)inch PVC pipe that rests on the canister floor 32 a. The height ofvelocity ring 52 is approximately five (5) inches, whereas the depth ofthe confined water 44 is typically about three (3) inches, as designatedby the broken line 44 a. In other words, the velocity ring 52 issupported on the floor 32 a, partially submerged in the confined water44. And since the velocity ring 52 is simply resting on canister floor32 a, the confined water 44 is free to flow under the velocity ring 52,filling the velocity ring 52 to substantially the same depth (that is,approximately three (3) inches deep) as designated by the broken line 44b. Other arrangements could be used, of course; for example, thevelocity ring 52 could be fastened to the canister floor 32 a, in whichcase some provision would possibly be required to allow the confinedwater 44 to flow into the velocity ring 52.

In the illustrated embodiment, the pipe arrangement 54 includes an upperpipe section 54 a having a diameter similar to that of the suction hose19 (an inside diameter of approximately one (1) inch in the illustratedembodiment) and secured to the outlet of vacuum port 38, a lower pipesection 54 b having a diameter of approximately two (2) inches extendingdown into the velocity ring 52, and an adapter 54 c coupling the upperand lower pipe sections 54 a and 54 b. In the illustrated embodiment,the upper pipe section 54 a is constructed of metal, whereas the lowerpipe section 54 b is constructed of PVC. And as illustrated, the upperface of the adapter 54 c also functions, along with one or more venturimount stand-offs 56, to support the baffle disk 59. The bottom of thelower pipe section 54 b is closed by a circular plate 58, and a smallcircular opening 60 in the sidewall of pipe section 54 b just above theplate 58 defines an exit port through which the dust-laden air enteringvacuum port 38 must pass. As suggested in FIG. 5, the diameter of thecircular opening 60 is significantly smaller than that of the upper pipesection 54 a: a diameter of approximately 9/16 inch in the illustratedembodiment. Other combinations of pipe could be used, but theillustrated arrangement has proven to be particularly efficacious fordust removal. As also shown in FIG. 6, the vacuum port 38 incorporates anumber of drilled bleeder passages 38 a that allow a small amount ofatmospheric air to pass though the vacuum port's housing and join thedust-laden airstream drawn into the pipe arrangement 54 through thesuction hose 19; this expedient has a relatively insignificant impact onthe dust suction capability of the apparatus, but significantly reducesnegative vacuum excursions within the canister 32 in the event thatairflow through the dust containment portion 11 or suction hose 19becomes partially or completely blocked for any reason.

The length of the pipe arrangement 54, particularly the length of thePVC pipe section 54 b, is chosen so that the sidewall opening 60 is nearthe canister floor 32 a, well submerged in the confined water 44 withinvelocity ring 52. Thus, the dust-laden air entering the vacuum port 38exits the circular opening 60 well below the surface of the confinedwater 44 in a high velocity stream that creates a high degree ofturbulence in the confined water within velocity ring 52, creating afrothy mixture that bubbles up and out of the velocity ring 52, and intothe interior volume of the canister 32. This turbulent mixing ofdust-laden air and confined water 44 within the velocity ring 52 tendsto very thoroughly saturate or wet the airborne dust so that the airreleased into the canister in the space between the confined water 44and baffle disk 59, and thereafter exhausted through the venturi 40 a isvirtually free of dust.

In summary, the vacuum dust extraction apparatus of the presentinvention operates to efficiently and effectively extract and capturedust produced by percussive impacting of an air tool's implement on aworkpiece. The various elements of the apparatus may be sizeddifferently than shown, and may be constructed of metal or plastic, asappropriate. And of course, it will be recognized that while theinvention has been described in reference to the illustratedembodiments, numerous modifications and variations in addition to thosementioned herein will occur to those skilled in the art. For example,the tubular coupler 12 snorkel 13 could be formed as one piece, and soforth. Accordingly, it will be appreciated that systems incorporatingthese and other modifications and variations still fall within theintended scope of the invention.

1. Vacuum dust extraction apparatus for an air tool that percussivelydrives an implement, comprising: a snorkel and bellows removablyfastened to the air tool and surrounding an exposed portion of theimplement for collecting dust produced when the implement percussivelyimpacts a workpiece; a suction hose coupled to an outlet of saidsnorkel; and an industrial vacuum coupled to said suction hose, thevacuum including a canister holding a volume of confined water, a lidsecured to a rim of said canister, a lid-mounted air inlet port to whichsaid suction hose is coupled, a down pipe extending downward from saidair inlet port into said confined water, and a lid-mounted pneumaticallypowered vacuum unit that creates a vacuum in said canister that drawsdust-laden air in said snorkel and bellows through said suction hose,said down pipe, and said confined water before exhausting water-filteredair through said vacuum unit.
 2. The vacuum dust extraction apparatus ofclaim 1, where: said air inlet port includes at least one vent openingthat allows atmospheric air to enter said air inlet port.
 3. The vacuumdust extraction apparatus of claim 1, further comprising: a cylindricalvelocity ring partially submerged in said confined water and supportedon a floor of said canister in a manner that permits said confined waterto enter a space enclosed by said velocity ring, and such that said downpipe extends downward into said space, and into the confined waterwithin said space.
 4. The vacuum dust extraction apparatus of claim 3,where: said velocity ring rests on the floor of said pail in a mannerthat permits said confined water to flow under said velocity ring andinto the space enclosed by said velocity ring.
 5. The vacuum dustextraction apparatus of claim 3, where: said down pipe extends downwardsubstantially to the floor of said canister; and said down pipe includesan underwater exit port proximate to the floor of said canister throughwhich the dust-laden air is released into the confined water within saidvelocity ring.
 6. The vacuum dust extraction apparatus of claim 5,where: said down pipe is closed at its end proximate to the floor ofsaid canister.
 7. The vacuum dust extraction apparatus of claim 5,where: said underwater exit port is formed in a sidewall of said downpipe.
 8. The vacuum dust extraction apparatus of claim 1, where saiddown pipe comprises: upper and lower sections joined by an adapter,where said upper second is coupled to said air inlet port, and saidlower section extends into said volume of confined water, said uppersection having an inside diameter similar to that of said suction hose,and said lower section having an inside diameter substantially largerthan the inside diameter of said upper section.
 9. The vacuum dustextraction apparatus of claim 8, where: the inside diameter of saidlower section is approximately twice as large as the inside diameter ofsaid upper section.
 10. The vacuum dust extraction apparatus of claim 1,where: an inboard end of said snorkel is fastened to said air tool via atubular coupler.
 11. The vacuum dust extraction apparatus of claim 10,where: said tubular coupler is removably fastened at a first end to afirst cylindrical sleeve formed on the inboard end of said snorkel, andat a second end to a second cylindrical sleeve of said air tool.
 12. Thevacuum dust extraction apparatus of claim 11, where: said first andsecond cylindrical sleeves are inserted into the first and second endsof said tubular coupler, and fastened thereto with removable retainerelements.
 13. The vacuum dust extraction apparatus of claim 10, where:said tubular coupler is removably fastened to a cylindrical sleeve ofsaid air tool.
 14. The vacuum dust extraction apparatus of claim 13,where said air tool includes a barrel, and a retainer locked onto saidbarrel to retain an inboard end of said implement within said barrel,and where: said air tool further includes an internal sleeve disposedwithin said retainer for limiting a percussive movement of saidimplement, and the cylindrical sleeve of said air tool is an extensionof said internal sleeve that protrudes through said retainer at anoutboard end thereof.
 15. The vacuum dust extraction apparatus of claim13, where said air tool includes a barrel, and a retainer locked ontosaid barrel to retain an inboard end of said implement within saidbarrel, and where: the cylindrical sleeve of said air tool is acylindrical sleeve formed on an outboard end of said retainer.
 16. Thevacuum dust extraction apparatus of claim 13, where said air toolincludes a barrel, and a retainer locked onto said barrel to retain aninboard end of said implement within said barrel, and where: thecylindrical sleeve of said air tool is a cylindrical sleeve formed on anoutboard end of an adapter that is removably fastened to said retainer.17. The vacuum dust extraction apparatus of claim 16, where: saidadapter is a clamshell that encases said retainer.